Peter Regin and Erik Karlsson scored goals in their NHL playoff debuts, and goalie Brian Elliott -- another playoff newcomer -- made 17 saves to backstop the Ottawa Senators to a 5-4 victory in Game 1 of the teams' quarterfinal playoff series Wednesday at Mellon Arena.

"I thought overall they played well," Senators coach Cory Clouston said. "I thought all three had some nervous moments at times. Most important thing is they contributed to the win. We know we have to be a little bit better the next game, but we got the win and that's the most important thing."

Regin helped that effort by scoring the Senators' first goal, driving to the net to bang in a juicy rebound off a Jason Spezza shot in the first period to tie the game 1-1. Karlsson's goal in the second period pushed Ottawa's lead to 4-2 moments after a Pittsburgh power-play goal.

"They've stepped up all year, they got better every game," Senators forward Chris Neil said of Regin and Karlsson. "They just feed off one another. If one scores the other has to score to match. They room together on the road, as well. They're inseparable -- we call them the twins."

It wasn't just the Senators' younger players stepping up. The veteran line of Neil, Chris Kelly and Jarkko Ruutu combined for 3 goals and 3 assists. Ruutu's goal at 9:40 of the third period ended up being the game-winner.

"That line seems … whenever we need some momentum, whether we need a hit, good defensive play, tonight it was three goals, they seem to find ways to contribute in a lot of different areas," Clouston said.Evgeni Malkin had a pair of power-play goals for the Penguins, and Craig Adams and Alex Goligoski also had goals. But goaltender Marc-Andre Fleury was less than stellar, allowing five goals on 26 shots and giving up a few big rebounds that wound up in the net.

"It's frustrating," Fleury said. "I hate giving up so many goals. It's tough. I can't do any more about it and I have to just be ready for the next one."

While Pens captain Sidney Crosby had 3 assists -- including one on Goligoski's goal with 2:24 remaining that cut the deficit to one goal -- Ottawa's top defense pairing of Anton Volchenkov and Chris Phillips held him to just two shots, both of which came in the final 6:17.

"I thought they did a good job," Clouston said. "He's very dangerous even if he had one shot on net. He made a great play at the end (on Goligoski's goal). We're not going to say it's one or two guys -- we're trying to do it by committee, we're trying to do it as a team. We're trying to get into shooting lanes, we're trying to blocks shots, trying to make sure we have numbers at the blue line. Did we do that all night? No, I thought there were a couple breakdowns, but otherwise I thought we did a pretty good job of that -- and we'll have to get better next game."

When his team wasn't better, Elliott was there to pick up the slack. He was screened on both of Malkin's power-play goals and had no chance to stop Goligoski's one-timer off a blind, backhand feed from Crosby from behind the net. He might have liked to have back Adams' backhand goal from the left circle that floated over his glove early in the third and made the score 4-3, but otherwise it was a solid playoff debut for the 25-year-old.

"I think you have to let it settle in a little bit," Elliott said. "I didn't think it would be as different. Every win is so meaningful. Especially the first one tonight. You saw the excitement after the buzzer went off. We believe in ourselves and we believe we can take it all the way."

Though Elliott allowed four goals on just 21 shots, Clouston was pleased with his goaltender's performance in his first playoff game.

"I thought at times he made some real key saves," Clouston said. "At times he might have looked a little bit nervous, but the most important thing is we got the win. It's not how you win, its making sure you do get the win. He'll be a little more comfortable next game and we'll be better."

Crosby said the difference for his team could be capitalizing on its opportunities. The Penguins had just 21 shots on goal, but missed the net on another 14 tries.

"We had a few chances around the net," Crosby said. "Staalsy (Jordan Staal) had a great chance early on and we had a few chances around the net that just didn't go in. That's going to be the difference. You can always say 'What if,' but at the end of the day, you have to find ways to win and we weren't able to tonight."

Contact Adam Kimelman at akimelman@nhl.comShift of the game: The game was tied, 1-1, when Ottawa's Mike Fisher was sent off for interference. The Penguins already had one power-play goal, but the Senators' penalty-killers, led by forwards Matt Cullen, Daniel Alfredsson, Chris Kelly and Jarkko Ruutu, and defensemen Chris Phillips, Anton Volchenkov, Andy Sutton and Matt Carkner, shut the Pens down, holding them without a shot. Less than three minutes later, Chris Neil scored to put the Senators ahead to stay.